Energy consumption of wireless communication industry is increasing with improvement on communication data rate and quality, and high energy consumption will become a constraint for future development of the communication industry no matter from a perspective of environmental protection or manufacturing cost of a communication device, so a design of an efficient and energy-saving communication system has already become an important direction of future communication development.
Multiple input multiple output (Multiple input multiple output; MIMO for short) technology has already been widely applied to communication systems of present stage and next generation due to characteristic of high spectral efficiency. Orthogonal Frequency Division Multiplexing (Orthogonal Frequency Division Multiplexing; OFDM for short) technology has already become a main access technology of next generation communication system standards due to high-frequency spectrum efficiency. Because the OFDM technology can convert a traditional multipath interference channel into a frequency domain non-interference parallel channel, the combination of the OFDM technology and the MOMI technology will become mainstream of the communication system in the future. In energy consumption of a downlink MIMO-OFDM system, power consumption of a base station occupies a great proportion, so minimization of the total power consumed by the base station makes a big contribution to constructing the efficient and energy-saving communication system under the condition that user equipment requirements for communication data rate is met.
In the prior art, there is a method in which the minimum multiplexing gain in the MIMO mode is calculated to judge whether there is a MIMO mode which is more energy-saving than a single input single output (Single input single output; SISO for short) mode, the optimal MIMO transmission mode is selected according to a certain criterion, and the power of a base station is saved through mode switch. However, a switch between the MIMO mode and the SISO mode is only suitable for point-to-point transmission, and the switch mode cannot realize radio frequency link switching under the condition of meeting demands of multiple user equipments in a multi-user equipment downlink MIMO-OFDM system.
To the above problem, a prior art proposes a solution for realizing energy saving of a base station by controlling the number of enabled radio frequency links and the number of occupied frequency resource blocks (Resource Block; RB for short) in the downlink MIMO-OFDM system according to service traffic. In the technical solution, when service load is lower than a reference threshold, the system schedules a part of the total frequency resources not to be occupied, then disables a part of the radio frequency links according to the occupation condition of the frequency resource blocks, and finally adjusts transmitting power of the enabled radio frequency link to ensure that a whole power spectral value is unchanged.
In the technical solution, a specific design method of the service reference threshold is not given, and the relation between the occupation condition of the frequency resource blocks and the disabled radio frequency link is also not specifically given, that is to say, the technical solution does not solve the problem on the minimization of the total power consumed by the base station in the downlink MIMO-OFDM system.